In this article we want to demonstrate that annotation of multiword expressions in the Prague Dependency Treebank is a well defined task, that it is useful as well as feasible, and that we can achieve good consistency of such annotations in terms of inter-annotator agreement. We show a way to measure agreement for this type of annotation. We also argue that some automatic pre-annotation is possible and it does not damage the results. 1 Motivation Various projects involving lexico-semantic annotation have been ongoing for many years. Among those there are the projects of word sense annotation, usually for creating training data for word sense disambiguation. However majority of these projects have only annotated very limited number of word senses (cf. Kilgarriff (1998)). Even among those that aim towards "all words" word-sense annotation, multiword expressions (MWE) are not annotated adequately (see (Mihalcea, 1998) or (Hajic et al., 2004)), because for their successful annot...